Endless belt conveyors typically utilize rubber or fabric or composition belts of flexible material trained over cylindrical rollers which are supported in a suitable framework. The belt is driven at a desired speed by one or more of the rollers, with a series of idler rollers underlying and supporting the belt both on the load flight of the belt and the return flight of the belt.
Due to numerous variable conditions and factors, the belt will not always run true and will tend to shift toward one side or the other of the conveyor and bring the edges of the belt into interference with the conveyor frame members with consequent injury and costly damage to the belt.
The invention is directed to means for monitoring and restoring the belt to running true before the belt has shifted sufficiently to rub against the conveyor framework or otherwise to cause damage to the belt or interruption of the material handling process.
The problem has attempted to be solved by the use of adjusting means on the conveyor rollers whereby an operator can occasionally modify the axis of rotation of a roller to compensate for an observed consistent shift of the conveyor belt in one direction. Somewhat elaborate electronic or electrical sensing and roller control means have also been devised to monitor the shift of the belt and adjust the rollers to restore the belt to running true.